Telephone metering devices have been available in the prior art for some years. These devices allowed the telephone user to gauge the amount of time elapsed during a phone call and by entering the cost of the call per minute, to compute and display the cost of the call. However, only recently have attempts been made to provide for a line selection device based on these costs.
One prior art reference (U.S. Pat. No. 4,751,728) discloses a computer driven line selection device which also provides call metering capabilities. This patent however, relies on the telephone user to provide call rate information. Because this system is dependent upon manual input, cost information must be continuously updated to prevent inappropriate line selection. Additionally, this patent provides for a device which only handles one user telephone and one outgoing telephone line.